When you change the Google docs Page setup too "Pageless" Google does not refresh the page. You will need to refresh the page so Co:Writer/Snap&Read can see the Doc.

If you set the default doc Page setup setting to "Pageless", you will only have to refresh the Google Doc you changed the default setting in. When you open a new or old Doc they will in open in the "Pageless" format and will be seen by Co:Writer/Snap&Read.